Road Salts

Winter months in northern Michigan are (normally) piled high with snow and ice, and increasingly alongside that winter wonderland is a plethora of salt. Road salts keep our streets and sidewalks safer for our travels, but are they also safe for our environment? We invite you to read this month’s blog post to learn about the environmental and health impacts of road salts and what you can do about it.

roadsalts

Road salts, also known as deicing salts or rock salt, are primarily used to melt snow and ice on roadways to improve driving conditions. The most commonly used road salt is sodium chloride, which is inexpensive and effective at melting ice. Other types of salts used include calcium chloride and magnesium chloride, which have lower freezing points and can work at colder temperatures.

In Leelanau County, the Road Commission uses an average of 3,500 tons of road salt per year on county roads and MDOT roads within the county. The amount of salt used daily is based on the road conditions throughout the winter season.

The use of road salts has undoubtedly saved countless lives by reducing accidents on icy roads. However, road salts are not without their downsides. One of the most significant concerns is their impact on the environment. When road salts are applied to roads, they eventually melt the ice and snow, forming a salty solution known as brine. This brine can run off into nearby water bodies, such as streams, rivers, and lakes, or seep into the ground and contaminate groundwater sources.

Impacts

The increased salinity in water bodies can have several adverse effects on aquatic life. Many freshwater organisms are not adapted to survive in high-salinity environments, and exposure to road salt can stress or kill them. Fish, frogs, and invertebrates that rely on clean water for their survival can suffer from impaired growth, reproduction, and overall health.

In addition, road salts can have long-term effects on vegetation and ecosystem health. The runoff from salted roads can infiltrate and damage soil, making it less hospitable for plant growth. Salt-tolerant species, such as the invasive Phragmites, can thrive in these conditions, outcompeting native plants and disrupting the natural balance of the ecosystem. Since Phragmites already thrives in many roadside culverts along Lake Leelanau, the high concentrations of salt in those areas give it another competitive advantage over other native wetland plants.

Furthermore, there are concerns about the impact of road salts on infrastructure. Salt can corrode metal structures, including bridges, guardrails, and vehicles. This corrosion not only reduces the lifespan of these structures but also poses a safety risk.

Solutions

While safety is of the utmost importance, there are ways in which to reduce the impacts of excessive salt use in the winter.

  1. Brine solutions: Instead of using solid road salts, some areas are using brine solutions. Brine, a mixture of salt and water, can be sprayed onto road surfaces before a storm, creating a thin layer that prevents ice from bonding with the pavement. This method reduces the amount of salt needed and minimizes runoff.
  2. Alternative salts: Researchers are investigating the effectiveness of using alternative salts, such as calcium magnesium acetate or beet juice, for deicing purposes. These compounds are thought to have less environmental impact compared to traditional road salts. Please note that these alternatives are still in development and are not recommended yet for household use.
  3. Mechanical methods: In regions with light snowfall, mechanical methods like plowing and scraping can be used to remove snow and ice from roads. While this method requires more manpower and equipment, it reduces the reliance on salts. Additionally, because salt becomes less and less effective at de-icing below 15-degree temperatures, switching to salt alternatives or adding sand for traction may be more impactful options.
  4. Education and best practices: Public education campaigns can raise awareness about the environmental impact of road salts and encourage responsible use. For instance, using the proper amount of salt and avoiding over-application can substantially reduce the amount of salt entering water bodies.

Ice and Snow, Take it Slow 

Ultimately, finding the right balance between road safety and environmental protection is crucial. While road salts play a vital role in winter road maintenance, it is essential to consider the potential consequences and explore alternatives to minimize their negative impacts. By adopting more sustainable deicing practices, we can maintain safe roads while safeguarding our freshwater resources and ecosystems for future generations. At the end of the day, slowing down on treacherous roads is one of the best things we can do to protect ourselves and our environment.

Resources

EPA Salt Resources 

Salt Smart Collaborative

Wisconsin Salt Wise

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